At 1001 hours CST on 12 May 1973, a Beech 35/C33 Debonair aircraft, registered VH-DHI, struck the ground near the top of a ridge three miles west-north-west of Myponga, South Australia. It was found that the aircraft had struck rising ground, some 750 yards from the coast near the top of a north-south ridge, while travelling in a westerly direction and in a substantially level altitude. The altimeter subscale was set to 1019 millibars, which was the current area QNH. An examination of the wreckage failed to reveal any evidence of a defect or malfunction in the aircraft which might have contributed to the accident.

On the afternoon of 27 October 1973 Fokker P27 Series 400 aircraft registered VH-TFM, operated by Trails-Australia Airlines was engaged on scheduled Regular Public Transport Plight NO. 1497 from Melbourne to Wynyard. It was under the command of Captain LI. Denheld with First Officer B.J. Widmer as the other flight crew member. The aircraft carried two hostesses and 28 passengers. In instrument meteorological conditions, and while offshore in the area between Wynyard and Devonport, the aircraft was reportedly flown at heights below the minimum altitude specified for IFR operations.

Mr. Pickard flew VH-TSF from Cambridge to the Andover agricultural airstrip at about 0630 hours in company with another Pawnee aircraft and pilot. The two aircraft were assigned to participate in a superphosphate spreading operation covering several properties in the Andover area. At about 0800 hours both pilots made a joint aerial inspection of the properties to be treated and they individually commenced operations at about 0835 hours.

The aircraft was crulstng in a southerly direction at an altitude of 4500 feet above mean sea level in clear weather conditions north of Mansfield when there was a substantial loss of engine power and smoke issued from the engine and entered the cabin. The pilot checked the engine controls and selected the mixture control to the idle cut-off position. He made a distress radio call to the Melbourne Flight Service Unit and reported that he had a suspected engine fire and intended to make a forced landing two miles north of Mansfield. A field to the left was selected by the pilot as being suitable for a forced landing and he planned to fly down the western side of the field and make a left turn of about 180 degrees to land to the north into a light northerly surface wind. As the aircraft descended the undercarriage was selected down and a left hand turn was commenced but, as the turn progressed,the pilot decided that the field which he had selected was unsuitable and that he would now land in the field adjacent to and to the west of that originally selected. At this stage the starboard wing dropped and, despite recovery action taken by the pilot, the aircraft veered to the right until it was heading some 45 degrees to the right of the intended final approach path at a very low height. The aircraft then struck the upper limbs of a large gum tree at a height of about 50 feet, passed through the upper section of the tree and dropped steeply' into a nearby small dam coming to rest in a level attitude in water some four feet in depth. Subsequent investigation indicated that the engine power loss was the result of an in-service failure of the No. 4 cylinder connecting rod big end bearing as a result of which the connecting rod had fractured and penetrated the crankcase.

On 16 August, 1973 a Piper PA30/160 aircraft, registered VH-MEM, crashed into the southern slopes of Mount Neville whilst on a private travel flight from Branxton, New South Wales, to Archerfield, Queensland. The four occupants were killed and the aircraft was destroyed. Examination of the wreckage failed to reveal any evidence of pre-impact structural failure, malfunction of systems, or any mechanical evidence which might have contributed to the accident. At the moment of impact the aircraft was in a climb and the engines were heard at high power immediately prior to impact. The height of the last sighting, the distance travelled and the impact height are in general agreement with the aircraft's normal climb capability. It is apparent, therefore, that the pilot did not appreciate the very dangerous relationship between the aircraft's climb capability and the rising terrain ahead.

The aircraft commenced operations from an agricultural airstrip on Warrawee Station at about 1100 hours on the day of the accident and, on each flight, some 860 kg of superphosphate was uplifted and spread on properties in the area. At about 1200 hours, when 13 flights had been completed, operations ceased temporarily while the personnel concerned had a meal break. The aircraft was then refuelled, operations recommenced about 1230 hours and six further flights were completed. After being reloaded with superphosphate, the aircraft commenced another take-off but at a point some 44 metres along the take-off path, the nose wheel support assembly collapsed. The aircraft skidded for 7 metres on the collapsed assembly until the structure dug into the ground and the aircraft nosed over. The pilot's compartment was partially crushed as the aircraft came to rest in an inverted position.

On 23 January, 1973, a Cessna 150G aircraft registered VH-KPH disappeared whilst on a travel flight from Latrobe Valley, Victoria, to Merimbula, New South Wales and no trace has been found of the aircraft or its occupants. An intense air, sea and land search commenced at first light on the next day and continued until 13 February 1973. Civil and military aircraft involved in the search flew 166 hours and covered an area in excess of 8000 square miles, within which the high probability areas were searched many times. Twenty-five sighting and hearing reports were investigated but no trace was found of the aircraft or its occupants.

Early in the day the pilot flew the aircraft from Mudgee to the airstrip situated about 4 mile south of the property on which superphosphate was to be spread. The weather was fine, the wind was calm and visibility was unrestricted. Although the pilot did not carry out a ground or aerial inspection of the property prior to commencing operations, nor did he obtain a specific briefing regarding the location of power lines on the property, he had carried out similar operations on this property periodically during the previous five years. As the aircraft approached the power line it banked to the right, apparently to follow the change in boundary direction and the raised left wing tip struck the cables resulting in a portion of the wing leading edge and upper surface fabric being detached. The aircraft slewed and rolled to the left and struck the ground In an inverted attitude 460 feet beyond the power line where it came to rest against a post and wire fence. A fierce fire occurred immediately.

Early In the day the pilot flew the aircraft from Bathurst to an airstrip on a property at Hobby's Yards arriving at about 0630 hours. In conjunction with the pilot of another aircraft operating from the same airstrip it was planned to spread superphosphate on a lightly timbered, relatively flat area. The weather was fine, the wind was calm and the visibility was unrestricted. The aircraft took off in a westerly direction and turned right as before to proceed northward to the nearby spreading area. This flight path entailed about 40 feet high, aligned east-west and flying across a line of widely spaced green gum trees, generally situated outside the spreading area. As the aircraft crossed this line of trees it struck the upper limbs of a dead tree which extended some 30 feet above the general height of the green gums. The aircraft crashed to the ground in a steep nose-down the dead tree.

At a speed estimated by the pilot as 80 knots, he observed fluctuations in the oil pressure gauge of the port engine and he closed both throttles and abandoned the take-off. The tail of the aircraft was well off the ground at this stage, the pilot therefore attempted to lower the tail but the aircraft became airborne for a short period. He then took control action to return first the mainwheels and subsequently the tail wheel to the runway. When all three wheels were on the ground, heavy braking was applied but the aircraft over-ran the runway, continued through the prepared over-run area and finally ran into a creek some 180 metres beyond the sealed end of the runway.